In only his third official appearance for Barcelona's first team, on 12 January 2012, Roberto scored his second goal, helping the visitors come from behind to win it 2–1 against CA Osasuna in the domestic cup (6–1 on aggregate).[10] On 16 December 2014, also in that competition, he netted his third, contributing to an 8–1 demolition of SD Huesca at the Camp Nou.[11]

On 20 August 2016, Roberto started as a right-back and provided two assists in a 6–2 home victory against Real Betis in the opening match of the campaign.[17] On 24 September, from the same position, he again contributed with two assists in a 5–0 away rout of Sporting de Gijón.[18]

Roberto plays predominantly in midfield, he is known for his versatility, pace, strength rigorous work rate, power with the ball and accurate passing.[25] In 2016–17 season under Luis Enrique, he played in seven different positions with Barcelona. Former Barcelona coach Luis Enrique praised Roberto and stated: “In a team like ours, except in goal, he could play in any position, it’s no surprise. The most difficult thing is doing it well all over the field and Sergi Roberto does that.”[26] He seems best suited as a box-to-box player.[27]